\begin{table}[H] \centering
\newcolumntype{C}{>{\centering\arraybackslash}X}

\caption{Descriptive statistics for Compustat data}
\begin{tabularx}{\textwidth}{lCCCC}

\toprule
{Statistic}&{Real sales}&{\% change in sales\_{t+1}}&{Real markup}&{\% change in markup\_{t+1}} \tabularnewline
\midrule\addlinespace[1.5ex]
Mean&1565.40&25.60&1.41&10.51 \tabularnewline
\midrule P 25&27.57&-5.35&1.06&-3.25 \tabularnewline
\midrule P 50&138.06&5.14&1.23&0.03 \tabularnewline
\midrule P 75&648.47&18.76&1.51&3.33 \tabularnewline
\midrule SD&8458.53&841.17&0.79&321.95 \tabularnewline
\midrule 
\bottomrule \addlinespace[1.5ex]

\end{tabularx}
\begin{flushleft}
\footnotesize \emph\{Notes:\}  The Compustat final dataset contains 242,155 observations for 20,252 firms across 67 years. Variables are in millions
\end{flushleft}
\end{table}
